Hypoxia and P. gingivalis Synergistically Induce HIF-1 and NF-κB Activation in PDL Cells and Periodontal Diseases

Figure 2

Expression of MMP-1 in PDL cells. (a) PDL cells were cultured under normoxic or hypoxic condition and stimulated with LPS-PG (1 μg/mL). Untreated cells cultured in normoxia served as control. MMP-1 mRNA expression was quantitated by real-time PCR after 2, 4, 8, 24, and 48 h. Statistical differences were analyzed by one-way ANOVA followed by different post hoc tests (Dunnett’s and Tukey’s multiple comparison test); a value < 0.05 was assumed as significant. ^# depicts a significant difference with respect to the time-matched control, indicates a significant difference between groups (means ± SD; ). (b) MMP-1 protein secretion by PDL fibroblasts was determined using the Quantikine enzyme-linked immunoabsorbent assay (ELISA) system according to the manufacturer’s instruction. Supernatants of PDL cells stimulated with or without LPS-PG (1 μg/mL) under normoxic or hypoxic condition were collected after varying time points (2, 4, 8, 24, and 48 h). Statistical differences were analyzed by one-way ANOVA followed by different post hoc tests (Dunnett’s and Tukey’s multiple comparison test); a value < 0.05 was assumed as significant. indicates a significant difference between groups (means ± SD; ).

(a)

(b)